Field of the Invention
The present invention relates to a photoelectric conversion device, and particularly relates to a photoelectric conversion device that outputs a reference signal.
Description of the Related Art
In the field of image pickup apparatuses, a signal serving as a reference for timing of an operation, such as correction, is known to be generated by an image pickup apparatus itself. Japanese Patent Laid-Open No. 5-308579 describes a technique in which an optical black region containing light shielded pixels includes position reference pixels that generate output signals different from those generated by the light shielded pixels. Also, Japanese Patent Laid-Open No. 5-308579 mentions that one position reference pixel is surrounded by light shielded pixels.
In a solid-state imaging apparatus described in Japanese Patent Laid-Open No. 5-308579, the output of position reference pixels may vary depending on, for example, the temperature, the use environment, or the length of storage time of the solid-state imaging apparatus. In particular, since one position reference pixel in the optical black region is surrounded by light shielded pixels, it is difficult to identify whether the read signal is based on the position reference pixel or is a specific signal generated by a defective light shielded pixel or the like. Also, since one position reference pixel is surrounded by light shielded pixels, a complex process is required to identify the start position of a row from read signals.